Got my hands on a W230SS with Maxwell. The thing overclocks like a beast. Haven't really pushed it extra hard but +135Mhz as per Kepler is possible. It also implements proper boost algorithm unlike its 650m sibling. Maxwell inst as brute powerful as the kepler equivalent but the core is utilized much better. Thus, you will notice more consistent performance. Additionally, the beefed up internal cache makes it much less vulnerable to Memory bandwidth on models with GDDR3 though I highly recommend getting the GDDR5 variant as much as possible.